This layer represents the relative summer density of beluga calves in the St. Lawrence Estuary based on 35 aerial surveys carried out from 1990 to 2009. The boundaries of the areas were determined by combining the highest densities until the desired proportion of the population was obtained using kernel density estimation in order to obtain a smooth and continuous density distribution. Within Fisheries and Oceans Canada (DFO), the ecosystem approach is considered as a tool for operational planning, project implementation and preparation of advisory reports. In response to this strategic direction, the DFO science division is committed to implement the ecosystem approach in its activities as Ecosystem Research Initiatives (ERI) in each of the six administrative regions of DFO. In the Quebec region, two pilot projects were implemented, of which one aimed to define and characterize the habitat of the St. Lawrence beluga (Delphinapterus leucas). Data sources and references: DFO. 2016. Ecosystem Research Initiative (ERI): Integrated Advice on the Summer Habitat of the St. Lawrence Estuary Beluga (Delphinapterus leucas). DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2016/030. Mosnier, A., R. Larocque, M. Lebeuf, J.-F. Gosselin, S. Dubé, V. Lapointe, V. Lesage, V., H. Bourdages, D. Lefaivre, S. Senneville and C. Chion. 2016. Définition et caractérisation de l'habitat du béluga (Delphinapterus leucas) de l'estuaire du Saint-Laurent selon une approche écosystémique. Secr. can. de consult. sci. du MPO. Doc. de rech. 2016/052. vi + 93 p.

To identify areas of high residency, fine-scale tracking data from individual animals and coarser, short-term movement patterns of herds were analyzed. Individual radio-tracking was assessed from 2001 to 2005 and herd visual tracking was assessed from 1989 to 2008. Data was collected by two research teams: GREMM (Groupe de recherche et d’éducation sur les mammifères marins) and Fisheries and Océans Canada (DFO). Areas of high residency were determined using net displacement speed of herds and they were defined as adjacent cells where 50% of the herds travelled at or below a threshold speed. Areas of high residency do not represent the general distribution of the beluga whale and no association between these areas and specific biological functions could be established. The exact delimitation of these areas can change according to the definition criteria used in the analysis. Therefore, the marginal cells are not necessarily indicative of lower habitat quality. Data source: Lefebvre, S., Michaud, R., Lesage, V. and Berteaux, D. (2012). Identifying high residency areas of the threatened St. Lawrence beluga whale from fine-scale movements of individuals and coarse-scale movements of herds. Mar. Ecol. Prog. Ser. 450: 243–257.

This layer represents the relative summer density of belugas in the St. Lawrence Estuary based on 35 aerial surveys carried out from 1990 to 2009. The boundaries of the areas were determined by combining the highest densities until the desired proportion of the population was obtained using kernel density estimation in order to obtain a smooth and continuous density distribution. Within Fisheries and Oceans Canada (DFO), the ecosystem approach is considered a tool for operational planning, project implementation and preparation of advisory reports. In response to this strategic direction, the DFO science division is committed to implement the ecosystem approach in its activities as Ecosystem Research Initiatives (ERI) in each of the six administrative regions of DFO. In the Quebec region, two pilot projects were implemented, of which one aimed to define and characterize the habitat of the St. Lawrence beluga (Delphinapterus leucas). Data sources and references: DFO. 2016. Ecosystem Research Initiative (ERI): Integrated Advice on the Summer Habitat of the St. Lawrence Estuary Beluga (Delphinapterus leucas). DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2016/030. Mosnier, A., R. Larocque, M. Lebeuf, J.-F. Gosselin, S. Dubé, V. Lapointe, V. Lesage, V., H. Bourdages, D. Lefaivre, S. Senneville and C. Chion. 2016. Définition et caractérisation de l'habitat du béluga (Delphinapterus leucas) de l'estuaire du Saint-Laurent selon une approche écosystémique. Secr. can. de consult. sci. du MPO. Doc. de rech. 2016/052. vi + 93 p.

This layer represents the seasonal distribution of St. Lawrence Estuary beluga whale population (Delphinapterus leucas). Summer distribution is based on many surveys conducted between the end of August and early September. Fall and winter distributions are based on aerial surveys conducted during mid-October, November and from December to March 1989-1990. Spring distribution is based on anecdotal reports and two aerial surveys conducted in late April and early June 1990. Beluga whale seasonal distribution can change according to sea ice cover, predation risk and food availability. This layer represents the general seasonal distribution and does not account for the sexual segregation among males and females in the St. Lawrence Estuary. This layer do not represent the beluga's critical habitat. See the data layer “Beluga whale critical habitat in the Saguenay River and the St. Lawrence Estuary” (https://open.canada.ca/data/en/dataset/fdfef550-b94c-466c-9dcb-24c297c00e3e). Data source : Mosnier, A., Lesage, V., Gosselin, J.-F., Lemieux Lefebvre, S., Hammill, M. O., Doniol-Valcroze, T. 2010. Information relevant to the documentation of habitat use by St. Lawrence beluga (Delphinapterus leucas), and quantification of habitat quality. DFO Can. Sci. Advis. Sec., Res. Doc. 2009/098. iv + 35 p.

This layer represents the seasonal distribution of the St. Lawrence Estuary beluga whale population (Delphinapterus leucas). Three groups are represented: females with calf, adult males and mixed sectors. Herd distribution was defined using Fisheries and Oceans Canada (DFO) published data about beluga whales (see references). Herd distribution areas are only valid during the summer, and the uses of these areas by the herds are unknown. Data source : Michaud, R. 1993. Distribution estivale du béluga du St-Laurent; synthèse 1986-1992. Can. Tech. Rep. Fish. Aquat. Sci. 1906: vi + 28 p.

A modelling analysis conducted by Fisheries and Oceans Canada (DFO) identified these areas as the most suitable habitat for Blue whales: Gulf of St. Lawrence, waters off the southern coast of Newfoundland, the region of Mecatina Trough, the Esquiman Channel and the continental shelf margin off Nova Scotia. They represent important areas for foraging, feeding and socializing for Blue whales. The sources of data used to determine these important areas (by the enclosing boxes method) and the annual and seasonal cycles of Blue whale travel patterns include, but are not limited to, radio and satellite telemetry, passive acoustic monitoring, line-transect aerial surveys, anecdotal reports of observations and modelling. This layer does not represent the general distribution of the Blue whale. Important areas have been identified by reviewing several sources of information and to the best of researchers' knowledge. Several information about Blue whales, their behaviour and habitat use are still unknown. Data is scarce in some areas during winter periods. Observation efforts mostly occur during the summer period, however, data sources can validate their presence during seasons when the observation effort is lower. The Mecatina trough region represents an important area based on historical and non-current data. The presence data per month refers strictly to the information available in the cited research document, and does not express the absence of the species outside the months when a presence was validated. The presented information is valid until the following research survey. Reference: Lesage, V., J.-F. Gosselin, J. W. Lawson, I. McQuinn, H. Moors-Murphy, S. Plourde, R. Sears. and Y. Simard. 2018. Habitats important to blue whales (Balaenoptera musculus) in the Western North Atlantic. DFO Can. Sci. Advis. Sec. Res. Doc. 2016/080: iv + 50 p.